Why is soft iron generally used as the core of electromagnet?
Soft iron is used because it does not retain its magnetism when the current is switched off; in other words, it does not become permanently magnetized. To start with, the armature lies with only a part of it inside the coil.
Why is it preferred to use iron as core in creating an electromagnet can you use pencil instead of iron nail?
The best core for an electromagnet is therefore the material with the highest relative permeability. Any material with a relative permeability higher than one will increase the strength of an electromagnet when used as a core. This huge relative permeability is why iron is the best core for an electromagnet.
Why electromagnets should have high retentivity?
The coercivity of an electromagnet should be low because if the coercivity is high then it will be difficult to control the magnetic field of the electromagnet. Retentivity: It is the ability of electromagnet which means that the electromagnet remains magnetized even after the removal of the magnetic field.
Does soft iron have high retentivity?
Soft iron have a low retentivity in general.
What is the retentivity and coercivity of soft iron?
(A) Iron. Then use the hysteresis curve of both soft iron and steel. Retentivity is the amount of magnetization left when an external magnetizing field is removed. Coercivity is the reverse external magnetizing field which is required to demagnetize the substance completely.
Why is soft iron easily magnetized?
Soft magnetic alloys are ferromagnetic materials that are easily magnetized and de-magnetized. They rely on various additions of phosphorus, nickel, and silicon to optimize magnetic induction, permeability, and coercive force.
Why does an iron core increase the strength of an electromagnet?
Lorna: Why is it that adding the iron core increases the strength of the electromagnet? The simple idea here is that the iron becomes magnetised so that now, not only do we have the magnetic field due to the electric current passing through the coils of wire, but also the additional field due to the magnetised iron.
What is the retentivity and coercivity for electromagnet?
Ferromagnets with high retentivity and coercivity are used as permanent magnets (hard magnets), while the ones with low retentivity & coercivity (soft magnets) are used as cores in electromagnets. But all ferromagnets have high permeability.
What do you understand by retentivity?
Definition of retentivity : the power of retaining specifically : the capacity for retaining magnetism after the action of the magnetizing force has ceased.
Is soft iron a electromagnet?
Electromagnets are made of soft iron because soft iron has. A. high susceptibility and low retentivity. Hint: Soft iron is a special kind of magnetic material which are generally used for making electromagnets because it gets easily magnetised and also loses its magnetism as soon as the inducing field is removed.
Is soft iron preferred to make an electromagnet?
Coercivity is the minimum value of magnetizing intensity(H). Hence, the best material used to make electromagnet is soft iron.
What is retentivity of soft iron?